I keep running into learn you some erlang[1] which seems to be a good online resource. The author of which also wrote the "Erlang in Anger"[2] book.

Then there is the BEAM book[3] which provides an deep dive into Erlang and the BEAM virtual machine.

I'm not the best person to ask since I'm only starting out on Erlang! I much prefer to code visually :)

[1] https://learnyousomeerlang.com [2] https://www.heroku.com/blog/erlang-in-anger/ [3] https://blog.stenmans.org/theBeamBook/